The federal ruling on triclosan and other antibacterial ingredients lends new support to longstanding warnings from scientists who say the chemicals can interfere with hormone levels.

Under a proposed rule, the agency will require manufacturers to prove that their antibacterial cleaners are safe and more effective than plain soap and water.

The agency’s proposal comes more than 40 years after the agency was first tasked with evaluating triclosan and similar ingredients. Ultimately, the government agreed to publish its findings only after a legal battle with an environmental group, which accused the FDA of delaying action.